1. Technical Field
The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus having a function of compressing image data for processing.
2. Related Art
An image forming apparatus such as a printer, a copy machine, or a multi-function apparatus compresses image data for processing using a predetermined compression method and stores the compressed data until the processing such as printing is actually started, in order to effectively use resources of a memory, a hard disk, or the like.
Here, the compression process may fail in the case where data after being processed does not satisfy a predetermined condition (for example, a predetermined amount of data, a compression rate, and the like). As a technique for solving this problem, a data processing method is disclosed where the compression method is changed and compression is re-performed from the beginning in the case where compression of one page of image data fails (for example, JP-A-9-216349).
However, in the method disclosed in JP-A-9-216349, first, a compression process is performed on the one page of image data by a lossless compression method. In the case where the compression process fails in the middle of the process, the compression method is changed to a lossy compression method, and the compression process is re-performed on the one page of image data from the beginning. Accordingly, in the case where the compression process fails, the processing time is increased. In addition, since the compression method is changed to the lossy compression method, image quality of the print result is degraded.
Here, in order to suppress an increase in the processing time described above, a method used in the case where the compression process fails where the compression method is changed and the compression process is re-performed from the point where the compression failed. However, when the compression method is changed in the middle of the one page of image data, differences occur in image quality of the one page, and a good print result cannot be obtained.